doc infrastructure (still) not OBJDIR-clean

[Dag-Erling Smørgrav]

Attempts to build the doc tree after 'make obj' fail because of stuff
like this:

===> en_US.ISO8859-1/articles/console-server
make: don't know how to make /usr/obj/usr/home/des/freebsd/doc/en_US.ISO8859-1/articles/console-server//usr/home/des/freebsd/doc/en_US.ISO8859-1/articles/console-server/../../../share/images/articles/console-server/tk0231-9-1.png. Stop
*** Error code 2

Stop in /usr/home/des/freebsd/doc/en_US.ISO8859-1/articles.
*** Error code 1

Stop in /usr/home/des/freebsd/doc/en_US.ISO8859-1.
*** Error code 1

Stop in /usr/home/des/freebsd/doc.

apparently it's doing ${.OBJDIR}/${.CURDIR}/${IMGDIR} instead of
${.CURDIR}/${IMGDIR}.

DES
-- 
Dag-Erling Smørgrav - des at des.no